Yesterday was a day for people in some states to vote in primary elections. Kansas Republicans unseated some of their own lawmakers who were seen as too willing to cooperate with Democrats, and we'll have more on that in a moment.

RENEE MONTAGNE, HOST:

We'll also report on a primary vote that affects this fall's contest to control the Senate. Democrats hold an advantage in the Senate now. Republicans have many opportunities to gain seats or even win control.

INSKEEP: And one of those opportunities is in Missouri. In a primary yesterday, Republicans chose their candidate to challenge Democratic Senator Claire McCaskill.

Here's St. Louis Public Radio's Tim Lloyd.

TIM LLOYD, BYLINE: Congressman Todd Akin's upset victory came straight out of right field last night. Polls had showed him trailing the other two major candidates, businessman John Brunner and former state treasurer Sarah Steelman.

During his victory speech, Akin thanked God, and said his campaign's prayers had been answered.

(SOUNDBITE OF SPEECH)

REPRESENTATIVE TODD AKIN: And this campaign is about reclaiming our Godly values, rebuilding the American dream, restoring the America that we love.

LLOYD: Initially, Brunner was reluctant to concede, but eventually he tipped his hat to Akin. Digging into his very thick wallet, the wealthy Brunner had spent almost $7 million of his own money to plaster ads on Missouri televisions.

Steelman, on the other hand, was quick to voice her support for Akin.

(SOUNDBITE OF SPEECH)

SARAH STEELMAN: And I'm really excited for him, because it's very important for him to beat Claire McCaskill. And I'm going to what ever I can to help him do that.

LLOYD: But analysts say it may be McCaskill who ultimately came out on top. During the primary, she ran this ad that calls Akin too conservative, then lists a handful of his GOP selling points.

(SOUNDBITE OF POLITICAL ADVERTISEMENT)

UNIDENTIFIED MAN: Akin would completely eliminate the Departments of Education and Energy and privatize social security.

LLOYD: Many around the state read the ad as a clear message that McCaskill likes her odds in a head-to-head with Akin, and wanted to tip the primary scales in his favor.

A recent poll by the St. Louis Post Dispatch showed she stacked up better against Akin than the other two candidates. But Republicans plan on giving her a run for her money, literally.